Which of the following diseases is a protein deficiency disease?

Kwashiorkor is a severe form of malnutrition caused specifically by protein deficiency, characterized by edema, liver enlargement, and skin/hair changes. It typically occurs when children are weaned from protein-rich breast milk to protein-poor diets. Eczema is inflammatory, night blindness is Vitamin A deficiency, and marasmus (not listed) is calorie deficiency.